Struct AVMetadataMachineReadableCodeObject

#[repr(C)]
pub struct AVMetadataMachineReadableCodeObject { /* private fields */ }

Available on crate feature AVMetadataObject only.

AVMetadataMachineReadableCodeObject is a concrete subclass of AVMetadataObject defining the features of a detected one-dimensional or two-dimensional barcode.

AVMetadataMachineReadableCodeObject represents a single detected machine readable code in a picture. It is an immutable object describing the features and payload of a barcode.

On supported platforms, AVCaptureMetadataOutput outputs arrays of detected machine readable code objects. See AVCaptureMetadataOutput.h.

See also Apple’s documentation

Implementations

impl AVMetadataMachineReadableCodeObject

pub unsafe fn corners(&self) -> Retained<NSArray<NSDictionary>>

The points defining the (X,Y) locations of the corners of the machine-readable code.

The value of this property is an NSArray of NSDictionaries, each of which has been created from a CGPoint using CGPointCreateDictionaryRepresentation(), representing the coordinates of the corners of the object with respect to the image in which it resides. If the metadata originates from video, the points may be expressed as scalar values from 0. - 1. The points in the corners differ from the bounds rectangle in that bounds is axis-aligned to orientation of the captured image, and the values of the corners reside within the bounds rectangle. The points are arranged in counter-clockwise order (clockwise if the code or image is mirrored), starting with the top-left of the code in its canonical orientation.

pub unsafe fn stringValue(&self) -> Option<Retained<NSString>>

Returns the receiver’s errorCorrectedData decoded into a human-readable string.

The value of this property is an NSString created by decoding the binary payload according to the format of the machine readable code. Returns nil if a string representation cannot be created from the payload.

impl AVMetadataMachineReadableCodeObject

Methods declared on superclass AVMetadataObject.

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

pub unsafe fn new() -> Retained<Self>

impl AVMetadataMachineReadableCodeObject

AVMetadataMachineReadableCodeDescriptor.

pub unsafe fn descriptor(&self) -> Option<Retained<CIBarcodeDescriptor>>

Available on crate feature objc2-core-image and non-watchOS only.

An abstract representation of a machine readable code’s symbol attributes.

The value may be nil if an abstract representation of a machine readable code object is not defined for the code type or could not be detected.

Methods from Deref<Target = AVMetadataObject>

pub unsafe fn time(&self) -> CMTime

Available on crate feature objc2-core-media only.

The media time associated with this metadata object.

The value of this property is a CMTime associated with the metadata object. For capture, it is the time at which this object was captured. If this metadata object originates from a CMSampleBuffer, its time matches the sample buffer’s presentation time. This property may return kCMTimeInvalid.

pub unsafe fn duration(&self) -> CMTime

Available on crate feature objc2-core-media only.

The media duration associated with this metadata object.

The value of this property is a CMTime representing the duration of the metadata object. If this metadata object originates from a CMSampleBuffer, its duration matches the sample buffer’s duration. This property may return kCMTimeInvalid.

pub unsafe fn bounds(&self) -> CGRect

Available on crate feature objc2-core-foundation only.

The bounding rectangle of the receiver.

The value of this property is a CGRect representing the bounding rectangle of the object with respect to the picture in which it resides. The rectangle’s origin is top left. If the metadata originates from video, bounds may be expressed as scalar values from 0. - 1. If the original video has been scaled down, the bounds of the metadata object still are meaningful. This property may return CGRectZero if the metadata has no bounds.

pub unsafe fn type(&self) -> Retained<AVMetadataObjectType>

An identifier for the metadata object.

The value of this property is an AVMetadataObjectType representing the type of the metadata object. Clients inspecting a collection of metadata objects can use this property to filter objects with a matching type.

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}

Trait Implementations

impl AsRef<AVMetadataMachineReadableCodeObject> for AVMetadataMachineReadableCodeObject

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AVMetadataObject> for AVMetadataMachineReadableCodeObject

fn as_ref(&self) -> &AVMetadataObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AnyObject> for AVMetadataMachineReadableCodeObject

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for AVMetadataMachineReadableCodeObject

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AVMetadataObject> for AVMetadataMachineReadableCodeObject

fn borrow(&self) -> &AVMetadataObject

Immutably borrows from an owned value.

impl Borrow<AnyObject> for AVMetadataMachineReadableCodeObject

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVMetadataMachineReadableCodeObject

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVMetadataMachineReadableCodeObject

const NAME: &'static str = "AVMetadataMachineReadableCodeObject"

The name of the Objective-C class that this type represents.

type Super = AVMetadataObject

The superclass of this class.

type ThreadKind = <<AVMetadataMachineReadableCodeObject as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for AVMetadataMachineReadableCodeObject

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for AVMetadataMachineReadableCodeObject

type Target = AVMetadataObject

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for AVMetadataMachineReadableCodeObject

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for AVMetadataMachineReadableCodeObject

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVMetadataMachineReadableCodeObject

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for AVMetadataMachineReadableCodeObject

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for AVMetadataMachineReadableCodeObject

const ENCODING_REF: Encoding = <AVMetadataObject as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for AVMetadataMachineReadableCodeObject

impl Eq for AVMetadataMachineReadableCodeObject